Steven Sinofsky, the former head of Microsoft's Windows division and current board partner at venture capital firm Andreessen Horowitz, ran into trouble while signing up for an Office 365 plan Wednesday.

Sinofsky, in a series of tweets, said he tried several times to sign up for an Office 365 Midsize Business plan, which costs $180 per user annually, but kept getting the message "try again later."

Sinofsky then tried signing up for the free trial version of Office 365 Midsize Business, but that also didn't work. Around 6 p.m. Pacific time, he took to Twitter for assistance.

Early Thursday morning, Microsoft Support checked back in with Sinofsky to see if he was still having problems, but appeared to forget he was trying to sign up for the cloud-based suite of Office apps. Sinofsky noticed.

@stevesi Good day! Are you still having issues downloading and installing Office? Let us know. Thanks! ^EH

We've reached out to Microsoft for comment and will update this story if we hear back.

Microsoft partners that witnessed the exchange between Sinofsky and Microsoft Support told CRN this is an example of why the channel plays an important role in selling and support of Office 365.

"This about sums up our experience with Microsoft support," Jerod Powell, co-founder and CEO of San Jose, Calif.-based Microsoft partner InfinIT Consulting, told CRN. "They don't know their product, and it would be impossible for them to scale support for this. Microsoft needs its partners to keep customers happy."

Another partner said Microsoft's support for Office 365 has long been in need of improvement.

"They failed to take into consideration basic design issues from the perspective of the customer and partners, and they have refused to listen to the need to address some of the most basic aspects for years," said the partner, who didn’t want to be named.

Provisioning errors with Office 365 are pretty rare: One Microsoft partner told CRN he runs into them in only about 1 percent of sign-ups, and clearing and re-assigning licenses usually fixes the problem.

While this is likely just an honest mistake by Microsoft Support, the timing is unfortunate, coming less than two weeks after Microsoft was widely criticized for its support response during major outages to its Lync and Exchange cloud services, which are part of Office 365.